880 likes | 1.29k Views
DNA TOPOLOGY: EXPERIMENTS AND ANALYSIS. De Witt Sumners Department of Mathematics Florida State University Tallahassee, FL 32306 sumners@math.fsu.edu. Isomers. Using Topology in Science. SYNTHETIC KNOT. Dietrich-Buchecker & Sauvage, Ang. Chemie 28 (1989), 189. KNOT IN A PROTEIN.
E N D
DNA TOPOLOGY: EXPERIMENTS AND ANALYSIS De Witt Sumners Department of Mathematics Florida State University Tallahassee, FL 32306 sumners@math.fsu.edu
SYNTHETIC KNOT • Dietrich-Buchecker & Sauvage, Ang. Chemie 28 (1989), 189
KNOT IN A PROTEIN J. Am. Chem. Soc. 118(1996), 8945
A Knot Zoo By Robert G. Scharein http://www.pims.math.ca/knotplot/zoo/ © 2005 Jennifer K. Mann
WRITHE & AVERAGE CROSSING NUMBER Writhe --average the sum of signed crossings over all projections (average number of crossings over all projections)
Strand Passage Topoisomerase
Strand Exchange Recombinase
Topological Enzymology Mathematics: Deduce enzyme binding and mechanism from observed products
TOPOLOGICAL ENZYMOLOGY • React circular DNA plasmids in vitro (in vivo) with purified enzyme • Gel electrophoresis to separate products (DNA knots & links) • Electron microscopy of RecA coated products • Use topology and geometry to build predictive models
Topoisomerase I ExperimentDean et al. J. Biol. Chem. 260 (1985), 4795
Toposides--Chemotherapy Topoisomerase Replication Fork